1. Technical Field of the Invention
This invention relates to a flap shutter for combo packing and carton packing, in which the packing opens automatically when unfastened. This especially implies the combo packing made of foil-laminated paper, in which substances like milk, fruit juices, all kinds of non-alcoholic drinks or even non-food items such as general liquids can be packed. The closure can also be used for combo packing or carton packing, in which free-flowing substances like sugar, powder, all kinds of chemicals and similar substances can be preserved and packed. When the closure functions for such combo packing, which are produced from laminates reinforced with plastic sheeting, then it is clear that they can also be used in simple paper or carton packing, which, owing to the absence of the laminated foils, can be tom quite easily.
The foil-laminated paper in case of combo packing is a laminated material, somewhat like paper or carton paper coated with plastic such as polyethylene and/or aluminum. The membrane liner thus comprises of aluminum or plastic sheeting, which is stuck on the inside of the combo packing with the carton layer of the packing. However, it can also be made of a PE coating, which is welded on to the inner side of the carton material of the combo packing by means of a high-frequency welding. The normal volumes of such packing made of laminated materials range from 20 cl up to 20 liters and more.
2. Description of the Prior Art
Plastic closures for sealing such combo packing are known in different embodiments. They comprise of a frame-type base element, to be welded on to the combo packing and a covering lid, which can swivel on that element, which covers the frame and hence seals the base element and is mostly provided with a guarantee, and the seal must be torn away for swiveling the covering lid for the first time.
A major disadvantage of these commercial closures is that the point, where the closure is placed on the combo packing, must be pre-treated, for which there are several variants. Often a hole is made there in the combo packing fitting in shape to the light opening of the closure, which is then sealed again later with a membrane liner. Only then the closure is placed on the punched hole on the packing, so that the membrane liner is removed when the covering lid of the closure is swiveled. To do this, for instance, a guide is extended in the opening of the base element. This is equipped on the top with a push button, which the user can press with his finger, after which the guide moves downward and thereby tears and presses down the membrane liner. However, this does not lead to a very clean outflow opening and the guide extends diagonally downward in the flow opening after being pressed down and thus obstructs the flow, unless it is pulled out again or cut away or tom away, which can only be done with difficulty. Moreover, pressing down the membrane liner with the finger is not always hygienic. The fingers can sometimes be dirty and unwanted bacteria can always reach the liquid unintentionally from the fingers.
In another variant the combo packing is weakened extremely at the point, where the closure is either stuck or welded on. For instance, the foil material is punched through except for the related membrane liner. This, however, requires extremely precise punching tools and punching machines. If a too deep punching is done, the membrane liner can be damaged or cut through and the combo packing can then no longer be sealed germ free. If a too low punching is done, then the consumers would have problems in opening the packing and can open it only by tearing away the closure of the combo packing with a lot of strength. Another pre-treatment makes use of the laser technology. Using a laser beam, the final piece of the combo packing to be punched out or to be removed is weakened, so that the sealing still stays intact by leaving the membrane liner undamaged. Even this pre-treatment is cumbersome and expensive. The laser beam must be tuned exactly to the laminated foil, so that it is neither too weak nor too strong. But since the laminated foils show certain tolerances in their strength because of their manufacturing, the setting for punching as well as for weakening with the help of a laser beam becomes an additional problem. This way or that way, expensive machines and devices are necessary. Moreover, the pre-treatments, no matter according to which method they are done, are to be done exactly at the correct point of the laminated foil, and accordingly, the plastic closures must be placed precisely over these pre-treated points. To do this, a lot of engineering effort is needed, which accordingly costs a lot.
Another disadvantage of the standard solutions is that after the first swiveling of the lid part, the closure must be opened through a separate manipulation, namely by pressing the membrane liner with the naked finger. However, this method of opening the membrane liner is unhygienic and in addition, the membrane liner is not always released completely and cleanly from the light area to the inside of the projecting margins. Rather, the membrane liner gets tom along the length of the opening of the closure somewhere in the middle range and is then not pressed downward in the inner space of the combo packing. This leads to a formation of brows on both the sides, which project downward in the inside of the combo packing and disturbs and restrict the free and clean outflow of the contents. If the combo packing is swiveled very strongly in the outflow position, then sufficient air may not get inside the combo packing, owing to the too little dimensioning of the opening. This leads to a bubbling i.e. to a discontinuous, squirt-like outflow of the contents, which makes it difficult to put an intended amount in a glass or in a jug.
No such closure is available, which provides such a big spout, through which a tablespoon or another similar measuring spoon can be inserted. The known carton packing for corn flakes and similar products are thus simple carton packing for a plastic bag kept in the packing. For opening, the carton packing must be tom away by hand, so that it can then be opened on the top by folding up the folded margins or else tearing the packing along a perforation. Only then one can grab the plastic bag inside, take it out a little, and then cut one corner of the bag with scissors or with a knife. The contents are then poured out by slightly tilting and shaking the carton packing, which, however, runs relatively uncontrolled. If such a packing is opened once, it cannot be sealed again cleanly. Here too, a closure with a pouring opening of adequate size would be desirable i.e. with at least 10 cm2 to 20 cm2 of pouring opening, which can be sealed again. For contents that are drawn out with a spoon, the closure must have such an opening i.e. possibly with a still bigger clearance, so that a tablespoon or another measuring spoon can be inserted inside the opening and the contents can be drawn out. Such a closure would then be suitable for combo packing and simple carton packing of all powder products, such as for milk powder, drink concentrates, rice, flour and food as well as non-food products having a similar consistency. Because the sealing is easier to achieve for granular products, essentially thinner laminates can be used than for packing for liquids, and the combo packing can also then be tom open relatively easily.
The known plastic closures also prove to be inadequate in a totally different aspect. Firstly, the outflow spout of the closures does not always have an advantageous embodiment, so that when the pouring is stopped, the liquid trickles down at the outer side of the spout and then flows down over the combo packing. This mess of the outflow is very annoying, because often the entire front side of the packing becomes dirty.
The lid part of the many standard closures is also not held reliably in the open position of the lid, so that the lid becomes loose in the region of the internal hinge between the lid and the lower part owing to material stresses and disturbs the out-flowing jet, unless one holds the lid consciously in the open position with one hand. In many cases, one hand is needed for holding the combo packing and for pouring, while the other hand holds a glass, in which the liquid is to be poured. In such cases, no hand is free for keeping the lid open and with the pouring hand, one can simultaneously keep the lid in its open position with great difficulty.
Moreover, the standard pouring out closures have less user-friendly sealing arrangements, which can ensure the first opening i.e. the first swiveling of the upper part of the closure. In some solutions, a guarantee tape must be ripped off, which must be held with two fingers. In practice, however, this proves to be quite difficult. For instance, if the user has applied hand lotion or cream to his hands, then it becomes difficult for him to rip-off the guarantee tape, as long as his fingers are greasy. Opening the closure with gloves is also just not possible. Finally, the resealing is also not satisfactory, because the closures themselves are not sealed sufficiently after swiveling the lid parts.